A Labrador cross is bouncing back to full health after losing her leg following a snake bite.

Missy was bitten while out for her daily walk with owner John Staniforth in St Mellons, Cardiff.

The pooch began to limp on the way back home - with Mr Staniforth, 62, and wife Alison, 55, thinking their beloved pet had simply scratched her leg. But it was just as well the couple decided to book an appointment with a vet, because by the following morning Missy's leg had swollen to three times its usual size.

After arriving at the PDSA charity's PetAid hospital, vets faced a battle against time to save the animal amid fears of renal failure and poisoning.

Vet nurse Karen Jones said staff had been quite shocked by what they saw.

"On examination we noticed two small puncture marks on her foot plus the clinical signs which indicated she may have been bitten by a snake," she added. "Things like this are very unusual but the signs are very dramatic - a dog can die within a week if they don't get any veterinary care as the liver and kidneys just shut down."

The medical team gave round-the-clock care to Missy for two weeks, but the leg refused to heal and left her owners with little choice but to opt for an amputation. Ms Jones said: "The problem seemed to be spreading up her whole leg to her elbow and extended to the under-arm area. There was nothing that we could do to stop her skin shedding and it was one of the worst cases that I've ever seen. Missy was becoming increasingly withdrawn and we decided that urgent action needed to be taken to save her life."

Mrs Staniforth described the decision to amputate as an agonising one.

She said: "My son didn't want Missy to have her leg amputated as he was worried about how it might change her. But she was becoming more depressed and hated having her leg dressed each day, and we knew that the infection was spreading through her body which could kill her. So after careful discussion, we came to the decision that the best course of action for Missy would be to have her leg amputated."

But despite the drastic nature of the treatment, Missy has bounced back. Mrs Staniforth said: "When we went to pick Missy up we couldn't believe what we were seeing. She was walking and running on three legs as if nothing had happened, she was back to her old self and we were so relieved that we'd made the right decision. I cannot thank the PDSA enough for what they've done. I wanted to give something back so I've decide to take up running and I'm hoping to do the Cardiff half marathon in October. Short of winning the lottery that's the only way I can pay them back for what they've done for Missy and all of us."